[MonetDB-users] values of type char(n) not always blank padded?
Hi,
I'm wondering if the following results of querying values of the type char(n) (here n = 50), is expected or an error, since char(n) defines a fixed-length, blank padded string:
sql>create table a2 (c1 char(5), c2 char(50)); operation successful sql>insert into a2 values ('abc', 'abc'), ('defg', 'defg'); 2 affected rows (2.848ms) sql>select c1, c2 from a2; +-------+----------------------------------------------------+ | c1 | c2 | +=======+====================================================+ | abc | abc | | defg | defg | +-------+----------------------------------------------------+ 2 tuples (1.655ms) sql>select '#' || c1 || '#' || c2 || '#' from a2; +------------------------------------------------------------+ | concat_single_value | +============================================================+ | #abc#abc# | | #defg#defg# | +------------------------------------------------------------+ 2 tuples (2.242ms) LQL The result of the first SELECT shows that c1 and c2 are blank padded (according to the SQL standard). The result of the second SELECT looks a bit strange, are the padding space characters removed or added after the last '#'? Is this the expected result or an error?
Thanks,
Jennie
On Sun, Apr 24, 2011 at 11:45:38PM +0200, Ying Zhang wrote:
Hi,
I'm wondering if the following results of querying values of the type char(n) (here n = 50), is expected or an error, since char(n) defines a fixed-length, blank padded string:
sql>create table a2 (c1 char(5), c2 char(50)); operation successful sql>insert into a2 values ('abc', 'abc'), ('defg', 'defg'); 2 affected rows (2.848ms) sql>select c1, c2 from a2; +-------+----------------------------------------------------+ | c1 | c2 | +=======+====================================================+ | abc | abc | | defg | defg | +-------+----------------------------------------------------+ 2 tuples (1.655ms) sql>select '#' || c1 || '#' || c2 || '#' from a2; +------------------------------------------------------------+ | concat_single_value | +============================================================+ | #abc#abc# | | #defg#defg# | +------------------------------------------------------------+ 2 tuples (2.242ms) LQL The result of the first SELECT shows that c1 and c2 are blank padded (according to the SQL standard).
Not really. Only the rendering appears to be "blank padded" as the max. allowed string length is used as columns width for rendering; the values are not blank padded; cf.
sql>\f Current formatter: sql sql>select c1, c2 from a2; +-------+----------------------------------------------------+ | c1 | c2 | +=======+====================================================+ | abc | abc | | defg | defg | +-------+----------------------------------------------------+ 2 tuples (1.281ms) sql>\fraw sql>select c1, c2 from a2; % sys.a2, sys.a2 # table_name % c1, c2 # name % char, char # type % 5, 50 # length [ "abc", "abc" ] [ "defg", "defg" ]
Stefan
The result of the second SELECT looks a bit strange, are the padding space characters removed or added after the last '#'? Is this the expected result or an error?
Thanks,
Jennie
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participants (2)
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Stefan.Manegold＠cwi.nl -
Ying Zhang